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45e2544584
composite type capability makes it possible to create a system view
based on a table function in a way that is hopefully palatable to
everyone. The attached patch takes advantage of this, moving
show_all_settings() from contrib/tablefunc into the backend (renamed
all_settings(). It is defined as a builtin returning type RECORD. During
initdb a system view is created to expose the same information presently
available through SHOW ALL. For example:
test=# select * from pg_settings where name like '%debug%';
name | setting
-----------------------+---------
debug_assertions | on
debug_pretty_print | off
debug_print_parse | off
debug_print_plan | off
debug_print_query | off
debug_print_rewritten | off
wal_debug | 0
(7 rows)
Additionally during initdb two rules are created which make it possible
to change settings by updating the system view -- a "virtual table" as
Tom put it. Here's an example:
Joe Conway
40 lines
1.2 KiB
MySQL
40 lines
1.2 KiB
MySQL
CREATE OR REPLACE FUNCTION normal_rand(int4, float8, float8, int4)
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RETURNS setof float8
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AS 'MODULE_PATHNAME','normal_rand' LANGUAGE 'c' VOLATILE STRICT;
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CREATE VIEW tablefunc_crosstab_2 AS
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SELECT
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''::TEXT AS row_name,
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''::TEXT AS category_1,
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''::TEXT AS category_2;
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CREATE VIEW tablefunc_crosstab_3 AS
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SELECT
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''::TEXT AS row_name,
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''::TEXT AS category_1,
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''::TEXT AS category_2,
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''::TEXT AS category_3;
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CREATE VIEW tablefunc_crosstab_4 AS
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SELECT
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''::TEXT AS row_name,
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''::TEXT AS category_1,
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''::TEXT AS category_2,
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''::TEXT AS category_3,
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''::TEXT AS category_4;
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CREATE OR REPLACE FUNCTION crosstab2(text)
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RETURNS setof tablefunc_crosstab_2
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AS 'MODULE_PATHNAME','crosstab' LANGUAGE 'c' STABLE STRICT;
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CREATE OR REPLACE FUNCTION crosstab3(text)
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RETURNS setof tablefunc_crosstab_3
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AS 'MODULE_PATHNAME','crosstab' LANGUAGE 'c' STABLE STRICT;
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CREATE OR REPLACE FUNCTION crosstab4(text)
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RETURNS setof tablefunc_crosstab_4
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AS 'MODULE_PATHNAME','crosstab' LANGUAGE 'c' STABLE STRICT;
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CREATE OR REPLACE FUNCTION crosstab(text,int)
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RETURNS setof record
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AS 'MODULE_PATHNAME','crosstab' LANGUAGE 'c' STABLE STRICT; |